The present invention relates to automotive turbochargers. More particularly, this invention relates to a boost control valve for automotive turbochargers that communicates with the interior of the automobile to allow for manual adjustment from within the automobile.
Turbochargers are well known accessories for race cars and other high-performance vehicles. These forced induction systems compress the air flowing into each cylinder of the automobile""s engine, so that more fuel may also be added, leading to the realization of more power from each cylinder. Turbochargers use the force of the exhaust air flow from an engine to drive a turbine that, in term, operates an air pump or compressor that pressurizes the air going into the cylinders.
It is well known that turbochargers do not provide an immediate power boost, but rather the turbine in the exhaust must reach a threshold speed before a boost is produced. Generally, there is a lag between the time when the gas is applied and the boost is realized. This turbo lag is lessened by reducing the inertia of the rotating turbine and compressor, thereby allowing them to accelerate more quickly upon application of the fuel and, thus, provide the boost sooner. The inertia of these rotating parts may be reduced by reducing the size, more particularly the weight, of the turbocharger. However, while a smaller turbocharger of less mass will respond more quickly at lower engine speeds, it may not be able to provide a significant turbo boost at higher engine speeds, and may also be in danger of rotating too quickly at high engine speeds.
Wastegates allow for the employment of smaller, lighter, turbines, while preventing these light turbines from spinning too quickly at high engine speeds. The wastegate works by sensing the boost pressure and, when the pressure gets too high, thereby indicating that the turbine might be spinning too quickly, some of the exhaust air flow may bypass around the turbine blades, thus slowing them down.
Various types of control valves for turbochargers are generally known. However, it is appreciated that there is a need in the art for a boost control valve that can be manually manipulated from within the interior or xe2x80x9ccockpitxe2x80x9d of the automobile. Some electronic boost controllers may be set and controlled from within the automobile, but, to date, no manual boost control valves have been provided. The present invention provides a manual boost control valve, for turbochargers employing wastegates, as generally described above, that can be manually set and controlled from within the automobile.
In general, the present invention provides a manual boost control valve for an automobile turbocharger of the type having a turbine that is spun by the air flow in the exhaust of the automobile, a compressor connected to the turbine to rotate therewith and thereby pressurize the air flow into the cylinders of the automobile, and a wastegate located in the exhaust of the automobile for bypassing a portion of the air flow in the exhaust around the turbine. This manual boost control valve includes an intake line having an inlet and an outlet, the inlet communicating with the air flow pressurized by the compressor. A restriction coupling having an inlet and an outlet communicates, at its inlet, with the outlet of the intake line, and, thus, receives air flow pressurized through the intake line. The inlet of an actuator line communicates with the outlet of the restriction coupling so as to receive air flow pressurized through the restriction coupling. An outlet of the restriction coupling communicates with the wastegate actuator of the turbocharger. The restriction coupling further includes a biased stopper blocking the connection between the outlet of the intake line and the inlet of the restriction coupling, such that the air flow pressurized through the intake line must be sufficient to move the biased stopper in order that any air would be able to flow through the restriction coupling and into the actuator line. Means for adjusting the degree of bias placed on the bias stopper is provided such that the degree of bias can be manipulated from within the cockpit of the automobile. By adjusting the degree of bias placed on the biased stopper, the conditions under which pressurized air will reach the wastegate actuator will be controlled so as to thereby control the turbocharger performance.
In operation, the wastegate actuator of the turbocharger receives air flow pressurized through the actuator line of the boost control valve, and the wastegate actuator communicates with the wastegate of the turbocharger for manipulating the wastegate in accordance with the pressure of the air flow received through the actuator line. The degree to which the wastegate is manipulated, and, thus, the degree to which the turbo boost is controlled, is dependent upon the pressure of the air flowing first through the intake line, then through the restriction coupling, and, thereafter, through the actuator line and into the wastegate actuator.